Displays can be created from an array of light emitting devices each controlled by individual circuits (i.e., pixel circuits) having transistors for selectively controlling the circuits to be programmed with display information and to emit light according to the display information. Thin film transistors (“TFTs”) fabricated on a substrate can be incorporated into such displays. TFTs tend to demonstrate non-uniform behavior across display panels and over time as the displays age. Compensation techniques can be applied to such displays to achieve image uniformity across the displays and to account for degradation in the displays as the displays age.
Consider an active matrix organic light-emitting device (AMOLED) display with NR rows and NC columns of pixels. Let Matrix X of size NR×NC represent the VT shift or the mobility index of the pixels across the screen. The problem is to estimate Matrix X with the minimum number of pixel measurement. Matrix X is used to adjust the input voltage of each individual pixel (compensation) to have a uniform intensity for all pixels of the screen.
There is a need to minimize the number of measurements to reduce the time interval required for non-uniformity compensation. This saving in time further allows repeating the same measurement multiple times to reduce the variance of the additive noise by averaging.